This invention relates to a terminal assembly for a circuit interrupter, and more particularly to a terminal assembly used with a circuit interrupter to connect a plurality of source terminals and a plurality of load terminals of a circuit interrupter to external electric conductors respectively.
High capacity circuit interrupters include a terminal assembly having a structure which is extremely strong and which has good electric insulation properties because such circuit interrupters generally produce a high electromagnetic force when a shortcircuit current flows therein. A general form of a conventional terminal assembly connected to a high capacity circuit interrupter has heretofore comprised a plurality of source terminals connected to circuits on the source side within the particular circuit interrupter and also to external electric conductors respectively, and a plurality of load terminals connected to circuits on the load side within the interrupter and also to external electric conductors respectively, the arrangement being that those source terminals are in spaced parallel relationship with associated load terminals, there being one pair of source and load terminals for each of the phases of the circuit interrupter. For example, the terminal assembly for three phase circuit interrupters has three pairs of source and load terminals disposed in parallel to one another. The plurality of the source and load terminals pairs have electrically insulating side plates therebetween and on outsides thereof, and a pair of metallic plates are disposed on the outer sides of the outermost side plates respectively. A plurality of bolts extend through the side plates and metallic plates and are fastened to the metallic plates by associated nuts thereby to fix the pairs of source and load terminals to one another.
From the foregoing it is seen that in the conventional terminal assembly, the source terminals, the load terminals and the side plates are assembled into separate units each including a plurality of the components and, after their assembling, the units are connected together into a unitary structure by bolt and nut means. Thus conventional terminal assemblies such as described above have been disadvantageous in that the assembling operation thereof is extremely difficult, and the electrically insulating side plates are also required to be thick because each of the outermost side plates is contacted by the metallic plate disposed outside thereof and a shortcircuit is apt to occur therebetween due to dielectric breakdown.
Accordingly it is an object of the present invention to provide a new and improved terminal assembly for a circuit interrupter capable of been easily assembled and having excellent electric insulation properties.